The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
A typical multiple speed transmission uses a combination of friction clutches, planetary gear arrangements and fixed interconnections to achieve a plurality of gear ratios. The number and physical arrangement of the planetary gear sets, generally, are dictated by packaging, cost and desired speed ratios.
While current transmissions achieve their intended purpose, the need for new and improved transmission configurations which exhibit improved performance, especially from the standpoints of efficiency, responsiveness and smoothness, and improved packaging, primarily reduced size and weight, is essentially constant.
Traditionally, to transfer oil to rotating clutches within a transmission, oil is fed to the rotating clutches via a rotating central member of the transmission. Centrifugal forces cause the oil to flow from the center of the transmission outward to the rotating clutches. To balance the oil flowing from the center of the transmission, a balance supply of oil is also directed to the clutches from an opposite side of the clutch, which also originates from the transmission central axis. Rotating clutches have used balance dams and shaft seals for oil transfer thereto. Speed changes affect the oil supply because it comes from rotating elements, which rotate at different speeds. For certain clutches, however, a more precise and steady flow of oil may be desired.
Accordingly, there is a need for an improved, cost-effective, compact multiple speed transmission, and in particular, a transmission that provides oil to a rotating clutch in a controlled manner.